Michael Mosley gave the low-down on fasting from an extreme 3.5 day, 50 calorie a day fast to alternate day fasting where you can literally eat what you want on non fast days. Both of these regimes seem quite extreme. The 3.5 day fast in particular is something only supermodels and masochists would attempt. The alternate day fast again doesn’t seem very sensible. Pigging out on cheeseburgers then eating like a rabbit the following day can’t be good for you.

The 5:2 diet seems like a sensible solution. It involves eating whatever you want for five days and calorie restricting on the other two days. For women this means eating no more than around 500 calories and for men 600 calories.

My first attempt at calorie restriction today was surprisingly easy. A large bowl of porridge for breakfast & an apple filled me up for most of the day. I’d like to say the small portion of tofu & stir fried vegetables I ate this evening filled me up, however I actually felt more hungry after eating my evening meal than I felt all day. I would normally have snacked but satisfied my hunger with herbal tea instead.

The physical benefits seem to outweigh any of the difficulties endured when fasting. After 5 weeks of calorie restriction Michael Mosley lost over 1st in body weight, his body fat fell by 7% and circulating levels of IGF-1 reduced by 50%. His blood glucose also reduced to safe levels, as did his cholesterol.

The obvious benefit for me is a reduction in IGF-1 (Insulin Growth Factor). IGF-1 is a hormone which we need when we are growing and levels are highest during periods of rapid growth however, a diet high in animal protein can increase levels of IGF-1 and research has demonstrated a causal link between an excess of this hormone and certain types of cancer.

The IGF-1 cancer-connection was familiar to me before watching this programme. Many with breast cancer will know of Jane Plant‘s work which examines the causal link between dairy products and cancers of the reproductive system. When her cancer returned for a fifth time, Jane looked to other cultures and realised that the majority of people of in the Far East where reproductive cancers are much less common, don’t eat dairy products. She made the connection between IGF-1 in dairy products and an excess in our diet, leading to cancers of the reproductive system.

Interestingly, Tamoxifen, the drug commonly given to pre-menopausal women after treatment for breast cancer also works by lowering circulating levels of IGF-1.

I’ve scoured the internet since watching this programme and found much evidence in support of fasting and cancer prevention. Genesis UK in Manchester studied the effects of intermittent fasting on women at risk of breast cancer, whilst trials in the US have looked at the benefits of fasting when combined with chemotherapy. Studies show that whilst fasting helps support healthy cells during chemotherapy, cancerous cells are still sensitive to the effects of the drugs. If something as simple as fasting can enhance the effects of chemotherapy, this is an area that definitely needs more research.

Since my diagnosis I’ve cut out most dairy products from my diet although I have a sneaky bit of goats cheese now and again. I’m on the way to becoming vegetarian but not yet cut out the Sunday roast. After watching this documentary it looks like I might also be converted to the 5:2 way of eating. For most, this diet is a preventive measure but for someone like me, already living with a life threatening disease, the outcome could be much more significant.